News

"Pre-natal exposure to paracetamol linked to increased risk of asthma in early childhood"

As published in the International Journal of Epidemiology this past Friday, April 11.

An international study done by the Centre for Research in Environmental Epidemiology (CREAL) and the Municipal Institute of Medical Research (IMIM-Hospital del Mar) with collaboration from the University of Aarhus in Denmark affirms the known link between pre-natal exposure to paracetamol, especially during the first trimester, and the risk of respiratory problems or the development of asthma in the first seven years of a child’s life.

These results are especially important if the fact that paracetamol is a widely used analgesic in the general population is taken into consideration, and that it is often the medicine of choice for pain relief in pregnant women, as its use during pregnancy is not contraindicated. The use of paracetamol had previously been associated with an increase in asthma in children and adults, but no far-reaching study had linked this effect to pre-natal exposure. The results reveal a 20% increase in children’s risk of suffering from asthma in the first 18 months, a risk that increases to 50% when the study is expanded to seven years of age.

For the study, the researchers selected 66,445 women from the Danish National Birth Cohort, a database that includes information about births from 1996 to 2003. Information was obtained relative to taking paracetamol and other medicines (from a list of 44 analgesics available in Denmark) during gestation. The mothers consented to participate in an interview to find out which babies had been diagnosed with asthma and/or had developed respiratory problems, and which had not, when the children were 18 months old. Of these, 12,733 were available to offer the same information when the children were 7 years old. The sample was expanded even further when access was granted to records for children under the age of 18 months who had been hospitalised due to asthma at the National Hospital of Denmark.

According to the study’s researchers Manolis Kogevinas and Cristina Rebordosa: “For the first time, sufficient scientific evidence is available to demonstrate the effects of paracetamol taken at any time during pregnancy on the foetus, as paracetamol penetrates the placenta and the foetus has a different metabolic capacity than an adult.” This prospective study appears to confirm the hypothesis that juvenile asthma may be initiated in utero, that is, during the pre-natal period.

The researchers conclude that it is necessary to continue to study the possible adverse effects related to the use of paracetamol during pregnancy, placing special emphasis on the duration of the effects and on the importance of the combination of pre-natal and post-natal exposure. However, given the high prevalence of juvenile asthma in our society, it is important to keep these results in mind and review the prescriptive use of paracetamol during pregnancy.

Reference: “Pre-natal exposure to paracetamol and risk of wheezing and asthma in children: A birth cohort study”. International Journal of Epidemiology 2008; 1-8. Doi: 10.1093/ije/dyn070